Portable power source and portable power source system

ABSTRACT

A portable power source system including a battery pack housing at least one secondary battery, wherein first and second internal terminals for connecting to a pair of external terminals are provided inside the battery pack, and two or more operations in different operating directions are required to connect the external terminals to the internal terminals. The battery pack includes external terminal inserting portions for inserting the external terminals, and the two or more operations include a first operation including inserting the external terminals into the external terminal inserting portions and a second operation in a direction different from that of the first operation. In a state before the first operation is performed, at least one of the internal terminals is shielded with a protective cover, and the protective cover recedes from a position for shielding the internal terminal, in conjunction with the first operation, the second operation or a combination of the first operation and the second operation, thereby enabling a connection of the external terminals to the internal terminals.

RELATED APPLICATION

This application is the U.S. National Phase under 35 U.S.C. §371 ofInternational Application No. PCT/JP2005/000010, filed Jan. 5, 2005,which in turn claims the benefit of Japanese Application No.2004-007701, filed Jan. 15, 2004, the disclosures of which Applicationsare incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a portable power source and a portablepower source system that include a battery pack, and more particularlyto a terminal structure of a battery pack.

BACKGROUND ART

Recently, cordless or portable applications have been increasinglyrealized also for equipment such as electric tools, and there is anincreasing demand for portable power source systems. While electrictools such as an electric screwdriver are widely used for businesspurposes in construction sites and the like since they can dramaticallyimprove working efficiency, they are also sold at places like homeimprovement stores and coming into use for the purpose of do-it-yourselfand the like.

Although nickel-cadmium batteries, nickel-metal hydride batteries andthe like are mainly used as the power sources for equipment such aselectric tools that have been adapted to use in cordless applications,these batteries have a heavy weight, and therefore the use of lithiumion secondary batteries, which are lightweight, has been attemptedlately. In addition to being lightweight, lithium ion secondarybatteries have a discharge voltage per battery that is about three timesas high as that of nickel-cadmium batteries or nickel-metal hydridebatteries, and thus are advantageous in applications requiring highoutput.

Lithium ion secondary batteries, however, may not be able to maintainthe battery performance such as the cycle life if the charge/dischargeconditions are not controlled appropriately. When they are dischargedunder a special condition, including, for example, a case in which thepositive terminal and the negative terminal are short-circuited, thebattery performance may be significantly impaired.

In portable power source systems used in electric tools and the like, asthe connecting mechanism between a battery pack and a mounting portionfor mounting that battery pack, those of the inserting type or thesliding type have been commonly used. However, a pair of connectionterminals included in the battery pack is often exposed to the outside.In addition, in the case of electric tools used for business purposes,it is often the case that a plurality of battery packs are prepared inadvance and these are replaced for use, in order to improve the workingefficiency. In such a case, it is conceivable that a battery pack havingterminals that are exposed to the outside thereof are placed in a toolbox. In the tool box, metallic tools or parts such as nails or screwsmay be placed, or the tool box itself may be made of metal. Due to suchexternal factors, there is the possibility that short circuit may occurbetween the terminals of the battery pack.

when the terminals of the battery pack are exposed to the outside, thereis also the possibility that charging may be performed with a powersource other than a dedicated charger. Also in such a case, the chargeconditions cannot be controlled appropriately, so that there is thepossibility that the battery performance may be significantly impaired.

There is a technique that proposes to cover the terminals with a coverin a portable power source system, except for when the battery pack isconnected to a dedicated charger or equipment, from the viewpoint ofobviating the problems as described above (see Japanese UnexaminedPatent Publication No. Hei 9-320554). In this case, short circuit willnot occur unless lead wires or the like are intentionally connected tothe terminals; however, short circuit or the like cannot be sufficientlyprevented since the terminals are exposed in a state where the cover isreleased.

There is also proposed a technique by which the terminals are providedinside the battery pack, rather than being exposed to the outside,thereby preventing short circuit (see Japanese Unexamined PatentPublication No. 2001-57204). However, by simply insertingoff-specification lead wires or the like into external terminalinserting portions, the lead wires or the like can be connected to theterminals, so that the possibility of charging/discharging of thebattery under inappropriate conditions has not been totally eliminated.

DISCLOSURE OF INVENTION

It is a major object of the present invention to prevent short circuitbetween the terminals of a battery pack in a portable power source and aportable power source system, while preventing charging with a powersource other than a dedicated charger, thereby avoidingcharging/discharging of the battery under inappropriate conditions. Itis also an object of the present invention to provide a portable powersource system that allows an easy connection between dedicated equipmentor charger and a battery pack.

The present invention relates to a portable power source comprising abattery pack housing at least one secondary battery, wherein the batterypack includes external terminal inserting portions for inserting a pairof external terminals, a first internal terminal and a second internalterminal for connecting to the pair of external terminals are providedinside the battery pack, and two or more operations in differentoperating directions are required to connect the pair of externalterminals to the first internal terminal and the second internalterminal.

The present invention also relates to a portable power source systemcomprising a battery pack housing at least one secondary battery and amounting portion for mounting the battery pack, wherein the mountingportion includes a pair of external terminals, the battery pack includesexternal terminal inserting portions for inserting the pair of externalterminals, a first internal terminal and a second internal terminal forconnecting to the pair of external terminals are provided inside thebattery pack, and two or more operations in different operatingdirections are required to connect the pair of external terminals to thefirst internal terminal and the second internal terminal.

The present invention further relates to a portable power source systemcomprising a battery pack housing at least one secondary battery and amounting portion for mounting the battery pack, wherein the mountingportion includes a pair of external terminals, the battery pack includesexternal terminal inserting portions for inserting the pair of externalterminals, a first internal terminal and a second internal terminal forconnecting to the pair of external terminals are provided inside thebattery pack, the first internal terminal and the second internalterminal are provided in positions that are in a space communicatingwith the external terminal inserting portions and that are displacedfrom given straight lines in an inserting direction in the externalterminal inserting portions, the pair of external terminals are movablefrom an initial position to a fixing position, while being inserted intothe external terminal inserting portions, and a connection of the pairof external terminals to the first internal terminal and the secondinternal terminal is established in the fixing position.

The portable power source of the present invention may be provided with,for example, a protective cover for preventing short circuit and aremaining capacity display means. It should be noted that the batterypack may include, in addition to the secondary battery, a cabinet forhousing the secondary battery, a protection circuit on charge for thesecondary battery, a protection circuit on discharge for the secondarybattery, a thermistor and a thermal fuse, for example.

As described above, the portable power source system of the presentinvention includes at least a battery pack and a mounting portion formounting that battery pack. Furthermore, when the mounting portion isincluded in equipment that uses the battery pack as its power source ora charger, the portable power source system includes that equipment orcharger. Examples of the equipment including a mounting portion formounting a battery pack include, but not limited to, an electric tool,an electric vacuum cleaner, an electric bicycle and an electricmotorbike.

In the portable power source and the portable power source system of thepresent invention, one of the pair of external terminals is connected toone of the first internal terminal and the second internal terminal, andthe other of the pair of external terminals is connected to the other ofthe first internal terminal and the second internal terminal. One of thefirst internal terminal and the second internal terminal constitutes apositive (+) terminal, and the other constitutes a negative (−)terminal. That is, one of the first internal terminal and the secondinternal terminal is connected to the positive electrode terminal of thesecondary battery, and the other is connected to the negative electrodeterminal of the secondary battery.

Ordinarily, the first internal terminal and the second internal terminalare provided in concealed positions that are other than the outermostsurface of the cabinet surrounding the secondary battery and thatcommunicate with the external terminal inserting portions. Furthermore,the first internal terminal and the second internal terminal areprovided in positions that are displaced from straight lines in theinserting direction in the external terminal inserting portions providedin the battery pack. Accordingly, two or more operations in differentoperating directions are required to connect the pair of the externalterminals to the first internal terminal and the second internalterminal.

The two or more operations in different operating direction includes,for example, a first operation including inserting the pair of externalterminals into the external terminal inserting portions and a secondoperation in a direction different from that of the first operation. Inthis case, a connection of the pair of external terminals to the firstinternal terminal and the second internal terminal is not established bythe first operation, and a connection of the pair of external terminalsto the first internal terminal and the second internal terminal isestablished by the second operation. A system in which two operationsare required in this manner is also referred to as a “double actionsystem”.

For example, in the case of mounting a battery pack to a mountingportion of predetermined equipment or a predetermined charger, the firstoperation includes inserting the pair of external terminals included inthe mounting portion into the external terminal inserting portion of thebattery pack. Further, the second operation includes, for example,sliding in a direction orthogonal to the direction of the firstoperation, or rotation about the inserting direction as the rotationaxis.

In a preferred embodiment of the present invention, in a state beforethe first operation is performed, at least one of the first internalterminal and the second internal terminal is shielded with a protectivecover. The protective cover prevents contacts of the internal terminalswith components other than predetermined external terminals to which theinternal terminals are to be connected. The protective cover may have ashape covering at least a portion of the internal terminal(s), a shapeshielding at least a portion of the traveling path of the externalterminal(s), or a shape other than these. There is also no particularlimitation with respect to the extent to which the protective covershields the internal terminal(s).

The protective cover needs to recede from the position for shielding theinternal terminal(s), in conjunction with the first operation, thesecond operation or a combination of the first operation and the secondoperation. As a result, it is possible to establish a connection of thepair of external terminals to the first internal terminal and the secondinternal terminal. For example, it is possible to adopt such a system inwhich, by the first operation including inserting the pair of externalterminals into the external terminal inserting portions, the protectivecover is pushed away in the inserting direction by the externalterminals.

When the first operation and the second operation constitute anoperation of mounting the battery pack to predetermined equipment or apredetermined charger, it is preferable that a battery pack mountingportion included in the predetermined equipment or predetermined chargerincludes a cover releasing element for causing the protective cover torecede from a position for shielding the internal terminals, inconjunction with the first operation, the second operation or acombination of the first operation and the second operation. Examples ofthe cover releasing element include those having a protruding shape andplaying the role together with the external terminals of pushing theprotective cover away in the inserting direction in the first operation.

The present invention is particularly effective when the secondarybattery included in the battery pack is a lithium ion secondary battery.The reason is that a lithium ion secondary battery is particularlyvulnerable to overcharge, and therefore requires a highly protectivefunction.

In the portable power source and the portable power source systemaccording to the present invention, the terminals of the battery packare not exposed to the outside, so that short circuit will not easilyoccur between the terminals of the battery pack. Therefore, the presentinvention is particularly effective for a portable power source and aportable power source system that include a battery pack for an electrictools for which there is a high possibility of short circuit between theterminals.

Furthermore, since two or more operations in different operatingdirections are required to connect the external terminals to theinternal terminals in the portable power source and the portable powersource system of the present invention, off-specification lead wires orthe like cannot be connected to the terminals of the battery pack evenwhen such lead wires or the like are inserted into the external terminalinserting portions, unless an operation in a direction different fromthat of the insertion is performed. Accordingly, it is possible to avoidcharging/discharging of the battery under inappropriate conditions, andthe battery characteristics will not be paired significantly.

Moreover, when two or more operations in different operating directionsare required to connect the external terminals to the internalterminals, it is difficult to establish the connection if the shape andthe position in the mounting portion of the external terminals do notcorrespond to the shape and the position inside the battery pack of theinternal terminals. Accordingly, it is extremely difficult to connectthe battery pack to equipment other than predetermined equipment or apredetermined charger, making it possible to obviating troubles thatcould result from misuse of the power source system.

When including a protective cover, the portable power source and theportable power source system of the present invention can more reliablyprevent short circuit between the terminals of the battery pack and aconnection of the terminals of the battery pack to off-specificationlead wires or the like. For example, even when an attempt is made tointentionally connect off-specification lead wires or the like to theinternal terminals of the battery pack, a contact of the lead wires withthe internal terminals can be prevented unless the protective cover isreceded, since the internal terminals are shielded with the protectivecover.

Further, when the portable power source and the portable power sourcesystem include a protective cover, the protective cover must be recededin order to establish a connection of the internal terminals to theexternal terminals, in addition to that two or more operations indifferent operating directions are required. Accordingly, it isextremely difficult to connect the battery pack to equipment other thanpredetermined equipment or a predetermined charger, and such aconnection can be prevented more reliably.

Furthermore, in the portable power source system of the presentinvention, it is possible to establish a connection between the batterypack and predetermined equipment or a predetermined charger in a verysimple manner.

It should be noted that when there is the possibility that short circuitmay occur between the terminals of the battery pack, or that theterminals of the battery pack may be connected to a power source otherthan a predetermined charger, the battery pack needs to include aprotection circuit on charge and discharge of the lithium ion secondarybattery.

A protection circuit on charge including a current regulating device isrequired during charging, since there is the possibility that thebattery performance may be significantly impaired if charging is notperformed with controlled maximum voltage and controlled current value.On the other hand, a protection circuit on discharge including a currentregulating device is required during discharging in order to prevent alarge amount of current flowing through the discharge circuit and anextreme decrease in the battery voltage in the case where short circuitoccurs between the terminals of the battery pack and where the terminalsof the battery pack are connected to equipment other than predeterminedequipment.

On the other hand, when there is no possibility that the terminals ofthe battery pack will be connected to a power source other than apredetermined charger, the current regulating device of the protectioncircuit on discharge may be omitted, for such reasons that a largecurrent required by specific equipment is temporarily allowed to flowduring discharging, and that the total amount of the discharge currentis regulated by the capacity of the secondary battery. Accordingly, withthe present invention, it is also possible to reduce the manufacturingcost for battery packs.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a battery pack according to oneembodiment of the present invention.

FIG. 2 is a top view of the battery pack according to the embodiment ofthe present invention.

FIG. 3 is a cross-sectional view of a relevant part of the battery packaccording to the embodiment of the present invention, showing a state inwhich a pair of external terminals are not connected to a first internalterminal and a second internal terminal of the battery pack.

FIG. 4 is a cross-sectional view of a relevant part of the battery packaccording to the embodiment of the present invention, showing a state inwhich the pair of external terminals are connected to the first internalterminal and the second internal terminal of the battery pack.

FIG. 5 is a cross-sectional view of a relevant part of a battery packaccording to another embodiment of the present invention, showing astate in which a pair of external terminals are connected to a firstinternal terminal and a second internal terminal of the battery pack.

BEST MODE FOR CARRYING OUT THE INVENTION

In this embodiment, a description is given, with reference to thedrawings, of a portable power source and a portable power source systemthat have a double action system in which a first operation of insertingexternal terminals into external terminal inserting portions of abattery pack is performed, and thereafter a second operation of rotationabout the inserting direction as the rotation axis is performed.

FIG. 1 is a perspective view of a battery pack 10 according to thisembodiment, and FIG. 2 is a top view thereof. FIG. 3 and FIG. 4 arecross-sectional views of relevant parts of the battery pack 10 accordingto this embodiment, respectively showing an unconnected state and aconnected state between a pair of external terminals 4 and 5 and a firstinternal terminal 6 and a second internal terminal 7 of the batterypack. FIG. 4 corresponds to a relevant part of a cross-sectional viewtaken on the line I-I in FIG. 2. In this embodiment, the battery pack 10per se constitutes a portable power source. Further, the battery pack 10and the pair of external terminals 4 and 5, which are included in amounting portion (not shown) for mounting the battery pack 10,constitute a portable power source system.

At least one secondary battery (not shown) is housed inside the batterypack 10. A cabinet tube portion 11 constituting the battery pack 10includes, at its top, external terminal inserting portions 1 forinserting the pair of external terminals 4 and 5, and an elementinserting portion 2 for inserting a cover releasing element 9. Theexternal terminal inserting portions 1 include wider width portions 1 ainto which the external terminals 4 and 5 are inserted in the firstoperation, and slit portions 1 b formed in an arch shape communicatingwith the wider width portions 1 a. The element inserting portion 2 is acircular through hole.

A protruding portion constituting a guide 3 is provided on the side faceof the cabinet tube portion 11. When the battery pack 10 is mounted to apredetermined mounting portion, the guide 3 moves along a groove formedin the mounting portion. The guide 3 plays the role of positioning thebattery pack 10 and the mounting portion in the first operation and thesecond operation, which constitute mounting of the battery pack 10 tothe mounting portion.

In the first operation, the external teals 4 and 5 are inserted into thewider width portions 1 a of the external terminal inserting portions 1.The external terminals 4 and 5 have L-shaped tips. Additionally, in thefirst operation, the rod-shaped cover releasing element 9 is insertedinto the element inserting portion 2, concurrently with the insertion ofthe external terminals 4 and 5. By the insertion of the externalterminals 4 and 5 and the cover releasing element 9, a disk-shaped,movable protective cover 8 made of resin is depressed. That is, in astate before the first operation is performed, the protective cover 8 ispushed upward by the force of a spring 12, and the first internalterminal 6 and the second internal terminal 7 are covered and shieldedwith the peripheral portion of the protective cover 8. The protectivecover 8 recedes from the position for shielding the first internalterminal 6 and the second internal terminal 7, in conjunction with thefirst operation.

In the subsequent second operation including rotation, the externalterminals 4 and 5 move along the slit portions 1 b. In FIG. 2, theexternal terminals rotate clockwise. In the end position of the secondoperation, the first internal terminal 6 and the second internalterminal 7 are disposed facing the L-shaped tips of the externalterminals 4 and 5, and the connection of the external terminals 4 and 5to the first internal terminal 6 and the second internal terminal 7 isestablished in that position. The first internal terminal 6 and thesecond internal terminal 7 are respectively connected to one and theother of the positive electrode terminal and the negative electrodeterminal of the secondary battery housed inside the battery pack 10.

By controlling, for example, the material of the protective cover 8, theposition and the shape of the cover releasing element 9 and the strengthof the spring 12, it is also possible to allow the protective cover 8 torecede only when the connection is made to the external terminalsincluded in predetermined equipment or charger.

After the connection of the external terminals 4 and 5 to the firstinternal terminal 6 and the second internal terminal 7 has beenestablished, the protective cover 8 is pushed upward by the spring 12,and thus plays the role of further strengthening the connection betweenthe external terminals 4 and 5 and the first internal terminal 6 and thesecond internal terminal 7.

In the portable power source and the portable power source system ofthis embodiment, the first internal terminal 6 and the second internalterminal 7 of the battery pack 10 are not exposed to the outside, sothat short circuit will not easily occur between the terminals of thebattery pack 10. Furthermore, since the first operation includinginserting the external terminals 4 and 5 into the external terminalinserting portions 1 and the second operation including rotation arerequired to connect the external terminals 4 and 5 to the first internalterminal 6 and the second internal terminal 7, even whenoff-specification lead wires or the like are inserted into the externalterminal inserting portions 1, those lead wires or the like cannot beconnected to the first internal terminal 6 and the second internalterminal 7.

Furthermore, since it is difficult to establish a connection if theshape and the positions in the mounting portion of the externalterminals do not correspond to the shape and the positions inside thebattery pack 10 of the first internal terminal 6 and the second internalterminal 7, it is extremely difficult to connect the battery pack 10 toequipment other than predetermined equipment or a predetermined charger.

Moreover, since the battery pack 10 is provided with the protectivecover 8, short circuit between the first internal terminal 6 and thesecond internal terminal 7, as well as a connection of the firstinternal terminal 6 and the second internal terminal 7 tooff-specification lead wires or the like, can be effectively avoided,and moreover, it is extremely difficult to connect the battery pack 10to equipment other than predetermined equipment or a predeterminedcharger.

Additionally, while it is preferable that the battery pack 10 isprovided with the movable protective cover 8 made of resin, theprotective cover is not essential. FIG. 5 shows a cross-sectional viewshowing a relevant part of a battery pack 20, which has a structuresimilar to that of the above-described embodiment, except for notincluding the movable protective cover, but including a fixed shieldplate 28 instead. FIG. 5 shows a connected state between a pair ofexternal terminals 24 and 25 and a first internal terminal 26 and asecond internal terminal 27 of the battery pack 20.

Also in the embodiment of FIG. 5, after the connection of the externalterminals 24 and 25 to the first internal terminal 26 and the secondinternal terminal 27 has been established, the shield plate 28 is pushedupward by a spring 22, so that it is possible to strengthen theconnection between the external terminals 24 and 25 and the firstinternal terminal 26 and the second internal terminal 27.

INDUSTRIAL APPLICABILITY

The portable power source and the portable power source system accordingto the present invention are useful in applications for which it isdesired that short circuit between the terminals of the battery packduring storage and the misuse are prevented, and are useful as aportable power source and a portable power source system for use in, forexample, an electric tool, an electric vacuum cleaner, an electricbicycle and an electric motorbike.

1. A portable power source comprising a battery pack housing at leastone secondary battery, wherein said battery pack includes anelectrically insulative cabinet, said cabinet including a positiveexternal terminal inserting portion for inserting a positive externalterminal, and a negative external terminal inserting portion forinserting a negative external terminal, provided inside of said cabinetso as not to be exposed outside said cabinet are a positive internalterminal and a negative internal terminal for connecting to saidpositive external terminal and said negative external terminal,respectively, further provided inside of said cabinet, are: a movableprotective cover facing said positive internal terminal, said negativeinternal terminal, said positive external terminal inserting portion andsaid negative external terminal inserting portion; and an elastic memberfor biasing said protective cover toward said positive internal terminaland said negative internal terminal, two or more operations in differentoperating directions are required to connect said positive externalterminal and said negative external terminal to said positive internalterminal and said negative internal terminal, respectively, said two ormore operations comprising: a first operation including inserting saidpositive external terminal and said negative external terminal into saidpositive external terminal inserting portion and said negative externalterminal inserting portion, respectively, so that said positive externalterminal and said negative external terminal abut to said protectivecover, thereby causing said protective cover to go against the biasingforce of said elastic member and to thus separate from said positiveinternal terminal and said negative internal terminal; and a secondoperation including rotation having a rotational axis in the directionof said first operation, said positive external terminal insertingportion has: a first wider width portion into which said positiveexternal terminal is inserted in said first operation; and a first slitportion, formed the manner of communicating with said first wider widthportion, along which said positive external terminal moves in saidsecond operation, said negative external terminal inserting portion has:a second wider width portion into which said negative external terminalis inserted in said first operation; and a second slit portion formed inthe manner of communicating with said second wider width portion, alongwhich said negative external terminal moves in said second operation,said positive internal terminal is provided on an end portion of saidfirst slit portion opposite an end portion thereof where said firstwider width portion is positioned; and said negative internal terminalis provided on an end portion of said second slit portion opposite anend portion thereof where said second wider width portion is positioned,a connection between said positive external terminal and said positiveinternal terminal and a connection between said negative externalterminal and said negative internal terminal are both not yetestablished in said first operation, a connection between said positiveexternal terminal and said positive internal terminal and a connectionbetween said negative external terminal and said negative internalterminal are both established in said second operation, and at endpositions in said second operation, said positive external terminal andsaid negative external terminal are pressed to said positive internalterminal and said negative internal terminal, respectively, by thebiasing force of said elastic member, via said protective cover.
 2. Theportable power source in accordance with claim 1, wherein said secondarybattery is a lithium ion secondary battery.
 3. The portable power sourcein accordance with claim 1, wherein when said two or more operations indifferent operating directions are completed, said positive externalterminal and said negative external terminal are simultaneously andelectrically connected to said positive internal terminal and saidnegative internal terminal, respectively.
 4. A portable power sourcecomprising a battery pack housing at least one secondary battery,wherein said battery pack includes an electrically insulative cabinet,said cabinet having a cabinet tube portion, said cabinet tube portionincludes, at a top thereof, a positive external terminal insertingportion for inserting a positive external terminal, and a negativeexternal terminal inserting portion for inserting a negative externalterminal, said positive external terminal inserting portion has a firstwider width portion, and a first slit portion formed in an arch shapefor communicating with said first wider width portion; and said negativeexternal terminal inserting portion has a second wider width portion,and a second slit portion formed in an arch shape for communicating withsaid second wider width portion, provided inside said cabinet tubeportion and behind said top thereof, are a positive internal terminaland a negative internal terminal for connecting to said positiveexternal terminal and said negative external terminal, respectively,said positive internal terminal is provided on an end portion of saidfirst slit portion opposite an end portion thereof where said firstwider width portion is positioned; and said negative internal terminalis provided on an end portion of said second slit portion opposite anend portion thereof where said second wider width portion is positioned,provided inside said cabinet tube portion is a movable protective coverfor shielding said positive internal terminal and said negative internalterminal, said cabinet tube portion has, at said top thereof, an elementinserting portion for inserting a cover releasing element, said movableprotective cover is brought into contact with the inner wall of saidcabinet by the elastic force of a spring from inside said cabinet tubeportion, two or more operations in different operating directions arerequired to connect said positive external terminal and said negativeexternal terminal to said positive internal terminal and said negativeinternal terminal, respectively, said two or more operations includingat least a rotational movement, said two or more operations comprising:a first operation including: passing said positive external terminal andsaid negative external terminal through said first wider width portionand said second wider width portion, respectively, for insertions intosaid positive external terminal inserting portion and said negativeexternal terminal inserting portion, respectively; and inserting saidcover releasing element into said element inserting portion so that saidcover releasing element abuts to said protective cover thereby causingsaid protective cover to go against the elastic force of said spring andto thus separate from said positive internal terminal and said negativeinternal terminal; and a second operation including rotation having arotational axis in the direction of said first operation, a connectionbetween said positive external terminal and said positive internalterminal and a connection between said negative external terminal andsaid negative internal terminal are both not yet established in thefirst operation, and a connection between said positive externalterminal and said positive internal terminal and a connection betweensaid negative external terminal and said negative internal terminal areboth established in the second operation, and at end positions in saidsecond operation, said positive external terminal and said externalterminal are pressed to said positive internal terminal and saidnegative internal terminal, respectively, by the elastic force of saidspring via said protective cover.